Method for explosive installation of studs



Nov. 1, 1955 c. R. WEBBER ET AL 2,722,004

METHOD FOR EXPLOSIVE INSTALLATION OF STUDS Original Filed Dec. 31, 1949FIG 6 FIG. 4:

476 F/C-Z 2.

21 FIG: 5.

United States Patent METHOD FOR EXPLOSIV E INSTALLATION OF STUDS CharlesR. Webber and Virginius R. Erickson, Portland, Oreg., assignors toPowder-Power Tool Corporation, Portland, 0reg., a corporation of OregonOriginal application December 31, 1949, Serial No. 136,186. Divided andthis application December 8, 1952, Serial No. 324,748

1 Claim. (Cl. 1-60) This application is a division of co-pendingapplication Serial. No. 136,186 filed December 31, 1949, for Stud forExplosive Installation, now Patent No. 2,637,241.

' The present invention relates to stud driving tools of the typeemployed for installing studs by explosive action in wall surfaces, suchas concrete and steel, and is concerned more particularly with theprovision of an improved method of holding a stud in a tool tofacilitate such driving and which facilitates the controlling of theeffective power or force applied to the stud from a standard explosivecharge.

In accordance with the instant invention the stud is provided with africtional portion or element preferably of a destructible material tohold the stud at a selected position along the barrel of the tool sothat the desired effective force from a standard explosive charge willbe applied to the stud. At the same time the frictional element being ofa removable or destructible character, is readily destroyed so that itis no longer a part of the stud at the time the stud is installed in thewall surface.

The above and other objects of the invention are attained in a preferredembodiment of the invention as described in connection with theaccompanying drawings, in which:

Figure l is an elevational View of a stud driving tool employing theinvention, with a portion of the tool adjacent the combustion chamberbroken away and shown in section to illustrate details of construction.

Figure 2 is a detailed enlarged view of a stud embodying the invention.

Figure 3 is a transverse sectional view of the stud taken as indicatedby the line 33 in Figure 2.

Figure 4 is an enlarged view of the stud as mounted in the barrel of thetool.

Figure 5 is a view of a modified form of stud mounted in the barrel.

Figure 6 is a sectional view of a second modified stud construction alsobeing shown as mounted in the barrel.

Referring to Figure 1, there is shown a stud driving tool of thecharacter described and claimed in the copending applications of Smithand Daugherty, Serial No. 124,078, filed October 28, 1949, for StudDriving Tool, and Erickson and Bullwinkle, Serial No. 130,818, filedDecember 2, 1949, for Stud Driving Tool, now Patent No. 2,679,645. Ingeneral, stud driving tools of this character are adapted to beseparated or broken into two halves including a rear half 10 whichcontains the various firing control parts including, for example, afiring pin carrier 11, and a front or barrel half 12 of the tool inwhich the barrel 13 is included. The barrel 13 is provided with anenlarged rear end 13a which has a threaded connection within the end ofthe firing pin carrier 11 to connect the two halves of the tool. Thebarrel 13 is also provided with an enlarged bore to receive a removablebreech plug 14 in which the explosive cartridge 15 is mounted for impactby the firing pin of the firing mechanism. With the parts disassembled,the breech 2,722,004 Patented Nov. 1, 1955 plug 14 is removed and theselected stud 17 is installed in the barrel, the cartridge 15 is placedin the breech plug 14, and the parts are reassembled as shown in F1gure1 for a firing operation. Firing is accomplished by plac ng the end ofthe barrel 13 against the surface into WhlCh the stud is to be drivenand pressing or telescopingthe barrel assembly 12 and the firing pincarrier 11 back into the other portions of the tool until a firingposition 1s reached, as disclosed in said applications, and theneffecting relative turning movement of the central housing and the endgrip 18 to fire the tool. At this time the deflector pad structure 19,yieldably mounted about the barrel 13 is engaged with the surface aboutthe area of engagement of the end of the barrel so as to provideprotection from flying particles of the wall surface upon explosiveinstallation of the stud.

Referring in particular to Figures 1, 2 and 3, the stud 17 is of specialconstruction and carries with it a frictional portion or element whichis used to frictionally hold or secure the stud in a selected adjustedposition in the barrel in accordance with the disclosure of thecopending application of Virginius R. Erickson and Benjamin B.Bullwinkle, Serial No. 135,744 filed December 29, 1949, for Stud DrivingTool and Method of Power Control.

The stud 17 includes the usual sharpened hardened point 17a and thehead, which in this case is threaded as indicated at 17b. Immediatelyadjacent its head the stud is provided with a frictionally mountedplastic ring whose internal diameter is such to fit snugly on the shankof the stud and whose external diameter is such as to be deformed asshown in Figure 4 when installed in the barrel of the gun. This ring 17cnot only serves as a frictional retainer for the stud but also servesinitially as a seal against which the explosive gases impinge upontrying to pass between the threaded portion of the stud and the barrel.The plastic ring 170 may be constructed of any suitable material such aspaper, plastic, rubber or the like, to be readily removable ordestructible, but is preferably of resilient sheet plastic material suchas cellulose acetate which is readily combustible so that the ring willbe destroyed by burning during the expelling of the stud from the tool.

In the modification of the invention shown in Figure 3, a disc or ring21 is shown attached by glue or by any suitable adhesive to the head endof the stud. Other than its location, the disc 21 has the samecharacteristics as the ring 17c of Figures 1-3.

In the Figure 6 modification of the invention, a layer or coating 22 ofmaterial of deformable character is molded or otherwise secured aboutthe entire head of the stud to engage within the barrel over asubstantial length thereof. The layer 22 is of sulficient diameter to becompressed slightly upon installation in the barrel to providefrictional positioning of the stud in the desired location along thebarrel. The coating 22 may be of suitable rubber material, or of aplastic, such as cellulose acetate.

In connection with all modifications of the invention, the material ofthe frictional retainer is preferably such that it is either completelyconsmned by the heat of the explosion, or is charred or carbonizedsulficiently thereby as to be friable and easy to remove from the stud.

From the preceding, it is seen that the method of holding a stud inplace in the bore of the stud driving tool is carried out by effectingfrictional engagement between the stud, preferably the shank thereof,and the bore of the tool, and this frictional engagement may be effectedby securing a frictional retainer of the character disclosed in thedrawing, on the stud prior to the time of installation in the bore ofthe stud driving too]. This installation is preferably carried out bypushing the stud with the retainer thereon into the bore so that theretainer which is in the form of a collar, serves to hold the'stud'inplace against sliding movement in either direction until the timeof firingof the tool; and in the preferredembodiment the stud is heldfirmly at two spaced locations, namely at the head which is the portionof largest diameter and'at the location where the frictional retainer isengaged between the bore and the stud. While the studs are usuallysuppliedby the manufacturer with the frictional. retainer in placethereon, such frictional retainers may be supplied separately and placedby the worker on the stud'just prior to the time of installation in thebore of the tool.

While we have shown and described certain preferred embodiments of theinvention, it will be apparent that the invention is capable of'bothmodification and variation from the form shown so that the scope thereofshould be limited only by the scope of the claim appended hereto.

We claim:

The method of holding a stud against sliding movement in eitherdirection in the bore of an explosively actuatedstud driving toolwherein the bore has a breech end and a muzzle end and wherein the studcomprises a body having a cylindrical head at its rearward end providingthe portion of greatest diameter of the body and a shouldercorresponding to the desired depth of penetration of said stud into asurface, and also having a penetrating shank at its forward endterminating in a sharpened point, which comprises securing a resilientfrictional element on said stud extending outwardly beyond the largestdiameter of said stud a sufficient distance as to slidably engage saidbore, inserting said stud with the frictional element thereon into saidbore forward end first through the breech end of the bore by applyingforce to said stud, and terminating the application of said force toplace said stud in a location spaced from said breech end and saidmuzzle end and to. cause the stud to be held against sliding movementin.either direction by frictional engagement of said frictional elementbetween the stud and said bore.

References Cited in the file of' this patent UNITED STATES PATENTS1,656,333 Lund Jan. 17,1928 2,061,835 Haines Nov. 24, 1936 2,221,157Temple Nov. 12, 1940: 2,380,204 Turechek July 10, 1945 2,499,227 MilesFeb. 28, 1950 2,637,241 Webber May 5, 1953 FOREIGN PATENTS 47,431Germany June 22,. 1889

